The present invention relates to a retaining device for axially retaining an annular flange against a radial face of a turbomachine rotor disk.
More precisely, the invention relates to an improvement to the retaining device described in patent application EP 1 498 579 A1 filed by the Applicant. Such a device enables an annular flange to be retained against a radial face of a rotor disk, said disk presenting in the radial face an annular recess that is defined by a plurality of walls, one of which is formed by the internal face of a rim that extends radially outwards, said flange presenting in its radially inner portion an annular base that bears against the radially outer wall of the recess, and a root extending from the base radially inwards into the recess of the disk. According to that invention, the retaining device further comprises a retaining ring constituted by a split ring disposed in the recess of the rotor disk, the retaining ring having an axially external face that bears against an axially internal face of the rim, an axially internal face that bears against an axially external face of the root, and a radially outer face that bears against a radially inner face of the base of the flange.
That retaining device, and in particular the retaining ring, is simple to make, inexpensive, and makes it easier to mount and remove the parts. Nevertheless, it presents certain drawbacks. In particular, in operation, the flange is subjected to axial thrust that runs the risk of tilting the retaining ring outwards from the recess in the rotor disk. Such tilting of the retaining ring can then lead to hammering wear of the rotor disk, with a risk of it bursting. The tilting of the retaining ring can also lead, after hammering wear, to it becoming disengaged from the recess and thus leading to the flange escaping from its housing.